Author Topic: RCA Model A-108 restoration help???  (Read 1409 times)

VinylAddict

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Re: RCA Model A-108 restoration help???
« Reply #30 on: March 23, 2017, 03:46:25 PM »
Yes, was trying to play an extra  original VG copy of Synchronicity.
I have a new cart kit on the way, so hopefully I can get something accomplished here in the next few days.
I ordered this kit.
http://www.thevoiceofmusic.com/catalog/part_detail.asp?PNumberBase=KCCA&SearchType=AssociatedItem&MfgName=&Categories=All

TC Chris

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Re: RCA Model A-108 restoration help???
« Reply #31 on: March 23, 2017, 07:43:23 PM »
And remember that playing stereo LPs on the device will rind up the disc.  Mono cartidges had no vertical compliance designed in.  The stylus just moved back and forth sideways.  Stereo discs and cartridges use both lateral--sideways--and vertical movement. The channels are are 45 degrees to the surface.  Don't play any stereo record that you want to keep.  It's like the 45 rpm record I found and played on the Sonora 78 rpm acoustic phonograph.  The steel needles and massive tone arm did the vinyl no favors.

Chris Campbell

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Re: RCA Model A-108 restoration help???
« Reply #32 on: March 23, 2017, 09:59:23 PM »
I should be OK playing stereo records with the new car I have coming though, correct? I posted the link in my last post.

TC Chris

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Re: RCA Model A-108 restoration help???
« Reply #33 on: March 23, 2017, 11:04:49 PM »
Well, probably so.  I see that it contains jumpers for mono, telling us that it's stereo.

Chris Campbell

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Re: RCA Model A-108 restoration help???
« Reply #34 on: March 26, 2017, 07:01:17 PM »
OK guys, custom mounted the KCCA cartridge kit from VoM, installed the new belt and bushings. My wife was in tears when I fired it up and gave her a demo. Everything works on the VM950. Everything. Excellent. The speed at "33.3" is approx 32.8, so it plays a bit slow. Any idea why?
I also notice there is a good wobble in the platter, which may have e something to do with the slow speed.
How do I get the wobble out of the platter? Could it be a bad sleeve or something?


TC Chris

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Re: RCA Model A-108 restoration help???
« Reply #35 on: March 26, 2017, 08:28:20 PM »
OK guys, custom mounted the KCCA cartridge kit from VoM, installed the new belt and bushings. My wife was in tears when I fired it up and gave her a demo. Everything works on the VM950. Everything. Excellent. The speed at "33.3" is approx 32.8, so it plays a bit slow. Any idea why?
I also notice there is a good wobble in the platter, which may have e something to do with the slow speed.
How do I get the wobble out of the platter? Could it be a bad sleeve or something?

What kind of "wobble"?  These turntables were stamped steel, and probably not manufactured to the same tolerances we came to expect later.  And as to speed, I think the same comment applies.  If you have cleaned and greased the changer and oiled its motor, I'd be tempted to call it good enough. If your wife is happy, you've accomplished something worthwhile.

Chris Campbell

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Re: RCA Model A-108 restoration help???
« Reply #36 on: March 26, 2017, 11:05:02 PM »
It's got a good amount of wobble, I doubt it's normal, but it may be.
My wife's happy, but I'm not haha.
When the motor bushings are installed, do they go between the plinth and motor, or between the screw head and motor?

I'm thinking it's between the plinth and motor (the idler sits lower when viewing it from up top). Is that correct?

TC Chris

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Re: RCA Model A-108 restoration help???
« Reply #37 on: March 27, 2017, 08:01:22 PM »
It's got a good amount of wobble, I doubt it's normal, but it may be.
My wife's happy, but I'm not haha.
When the motor bushings are installed, do they go between the plinth and motor, or between the screw head and motor?

I'm thinking it's between the plinth and motor (the idler sits lower when viewing it from up top). Is that correct?

TC Chris

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Re: RCA Model A-108 restoration help???
« Reply #38 on: March 27, 2017, 08:04:46 PM »
It's got a good amount of wobble, I doubt it's normal, but it may be.
My wife's happy, but I'm not haha.
When the motor bushings are installed, do they go between the plinth and motor, or between the screw head and motor?

I'm thinking it's between the plinth and motor (the idler sits lower when viewing it from up top). Is that correct?

Let's try again.  If you mean the rubber isolation washer or bushing, in most changers I've see the answer is "both."  In fact, most of the ones Ive seen are poked through the sheet metal hole, like a grommet, so a portion is on each side.  The idea is to isolate motor vibration from the changer.   Does that look right for yours?

Chris Campbell

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Re: RCA Model A-108 restoration help???
« Reply #39 on: March 27, 2017, 11:42:09 PM »
Yeah, that sounds right, I ordered some new mounts and hoping it helps with the wobble. I think the motor/idler wheel is sitting about an 1/8" too high, I can hear it scrape on the platter on occasion.

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Re: RCA Model A-108 restoration help???
« Reply #40 on: April 01, 2017, 06:42:59 PM »
Replaced the motor mounts in  the VM930. Now the idler wheel doesn't want to spin once it gets any tension on it.
What happened?
It was working great before I put the correct mounts in.

TC Chris

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Re: RCA Model A-108 restoration help???
« Reply #41 on: April 01, 2017, 08:32:54 PM »
Take the platter off.  Try to position the idler wheel about where it would be with the platter in place.  Try to visualize what's causing it to bind.

Chris Campbell

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Re: RCA Model A-108 restoration help???
« Reply #42 on: April 01, 2017, 09:54:48 PM »
That's just it, as soon as I take any pressure off the idler wheel (not touching the plinth) the idler wheel spins perfect. When I let it have any tension against the plinth, it wants to stop or slow way down.
All this is with the platter off, obviously.
Anyone know where I could obtain a new platter (mine appears to have been repaired at one point, and this is what causes the warp I was referring to earlier.

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Re: RCA Model A-108 restoration help???
« Reply #43 on: April 06, 2017, 12:32:04 PM »
More help please :)
I'm currently working on the RP 190.
I disassembled everything on it (slider, motor, etc) except for the platter.
I can't get the platter to spin at 45 rpm. It's spins at a consistent 13.2 rpm. It doesn't fluctuate at all.
The idler wheel looked perfectly fine to me, but I used some rubber rejuvinator on it anyway.


VinylAddict

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Re: RCA Model A-108 restoration help???
« Reply #44 on: April 06, 2017, 04:12:16 PM »
I just received the motor a few times and still no change either.
Time for a new motor?